Cwa-app-ios: Risk check: Fallback strategy after bad internet connection presents 2*14 key files to ENF

[ndegendogo]

Avoid duplicates

• [X] Bug is not mentioned in the FAQ
• [X] Bug is not already reported in another issue

Describe the bug

• App is closed, last background check was less than 24 hours ago
• disable internet connection (both WLAN and mobile data).
• wait till the check is due plus two hours, to be sure to get the fallback strategy
• enable internet again, and wait another two hours
• don't open the app, check the exposure logs of ENF

Expected: see log entries of 14 files
Observed: two iterations of log entries (2*14 files)

See attached export file of exposure logs

Expected behaviour

only a single iteration (14 files)

Steps to reproduce the issue

see above

Technical details

• CWA version: 1.3.0(6)
• iOS Version: 13.6.1
• Device:iPhone 8

Possible Fix

Additional context

I have seen this pattern (27 or 28 files in the ENF log after delayed check > 26h) several times before, with cwa 1.2.1(0) and cwa 1.3.0(6), although I was not sure about bad internet connection. See here and here and here.

Today I could reproduce it explicitely by turning internet off while the check was due.

ExposureChecks-2020-09-07.json.zip

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Internal Tracking ID: EXPOSUREAPP-2589

[Marco2907]

Hi @ndegendogo , thanks for sharing your content. I will keep this issue to discuss this with our development team and come back to you as soon as possible.

Thanks,
MP

Corona-Warn-App Open Source Team

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Internal Tracking ID: EXPOSUREAPP-2589

[Marco2907]

Hi @ndegendogo , this risk check issue should be fixed with 1.4.0

Thanks,
MP

Corona-Warn-App Open Source Team

[ndegendogo]

Thanks @Marco2907
Do you have a planning / timeline for this release?

[Marco2907]

Hi @ndegendogo, it should be fixed in 1.4 and 1.4 should be released on October 10th.

Thanks,
MP

Corona-Warn-App Open Source Team

[ndegendogo]

Thanks again!

May I ask which commit(s) / PR / or item in the release notes relates to this issue?

[marcussc]

@ndegendogo https://github.com/corona-warn-app/cwa-app-ios/pull/1081 :)

[GPclips-zz]

Hello @ndegendogo,

this issue has been completed and will be closed now.

Thank you,
LMM

Corona-Warn-App Open Source Team

[GPclips-zz]

Hello @ndegendogo,

I will reopen the issue since the fix hasn't been deployed. Until then, we will leave the thread open.
We expecting the fix to be deployed as soon as possible.

Thanks,
LMM

Corona-Warn-App Open Source Team

[Ein-Tim]

@ndegendogo

Can you still reproduce this behavior in Version 1.5.0 or newer?

[ndegendogo]

@Ein-Tim I'll test again and report my observations.
Might have to wait for a few days (currently the check is deep in the night while I am sleeping).

[ndegendogo]

Tested scenario again today. Did behave as expected.
Thanks for fixing.

cwa 1.5.2 (1) / iOS 14.1 / iPhone 8

closing the ticket.